Europop plays from tiny speakers, hidden high up in the shadows.
Those to legalise sex work include Germany, the Netherlands, Austria, Switzerland, Greece, Turkey, Latvia and Hungary, although all still crack down on forced prostitution.
He says that, in a country where there are approximately 400,000 prostitutes and in a city where there are about 500 brothels, he needed a new approach to stand out.
Klaudia has a 17-year-old daughter.
Hydra, an organization that fights for prostitutes' rights in Germany, estimates there are close to half a million sex workers in Germany.
They have a limited education and they are travelling abroad for the first time.
They will give you an hour free.
It is a bit of a throwback in time, it even has Diskothek written in neon letters on the front.